JP3982022B2 - Single crystal manufacturing method and single crystal manufacturing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a single crystal manufacturing method and a single crystal manufacturing apparatus for growing a single crystal on a single crystal substrate using a sublimation recrystallization method, and in particular, manufacturing a bulk silicon carbide (SiC) single crystal or a GaN single crystal. It is suitable to be applied to a method and a single crystal manufacturing apparatus.
[0002]
[Prior art]
Conventionally, a sublimation recrystallization method has been widely used as a method for producing a single crystal such as silicon carbide. In this sublimation recrystallization method, a single crystal is manufactured using a graphite crucible composed of a cup-shaped crucible body having an open surface and a cover material covering the opening surface of the crucible body as a reaction vessel. .
[0003]
Specifically, a crucible body filled with a single crystal raw material is attached with a lid material on which a single crystal substrate serving as a seed crystal is fixed, and then the single crystal raw material is heated and sublimated at a predetermined temperature and a single crystal that is a seed crystal. The single crystal is recrystallized on the single crystal substrate by keeping the temperature of the crystal substrate lower than that of the raw material and holding the inside of the graphite crucible at a predetermined pressure.
[0004]
[Problems to be solved by the invention]
When a single crystal is grown in a graphite crucible, the Si / C ratio fluctuates because silicon (Si) or a gas phase species containing silicon reacts with carbon (C) which is the material of the graphite crucible. easy. For this reason, the Si / C ratio fluctuates until the temperature of the single crystal raw material, the temperature of the single crystal substrate, and the pressure in the graphite crucible reach predetermined conditions. Is not formed on the single crystal substrate.
[0005]
Further, since the single crystal substrate is exposed until the temperature of the single crystal raw material, the temperature of the single crystal substrate, and the pressure in the graphite crucible reach the respective predetermined conditions, the Si / C It is difficult to avoid the formation of Si droplets in the seed crystal and the mixing of graphite fine particles and metal impurities due to the change in the ratio. These contaminants cause various defects, which makes it difficult to produce a high-quality single crystal with few defects.
[0006]
The present invention has been made in view of the above problems, and avoids the influence of Si / C fluctuations and the generation of Si droplets resulting from this, and the incorporation of graphite fine particles and metal impurities into a single crystal, resulting in high quality with few defects. It is an object of the present invention to provide a method and an apparatus for producing a single crystal capable of producing a single crystal.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the following technical means are adopted.
In the invention according to claims 1 to 4, the temperature until the temperature of the raw material (2) and the seed crystal (5) reaches a predetermined temperature and the time when the pressure in the reaction vessel (1) reaches the predetermined pressure. Covers the seed crystal (5) with the shielding plate (6), blocks the sublimation gas of the raw material (2) from the seed crystal (5), and then moves the shielding plate to transfer the raw material (2) to the seed crystal (5). The sublimation gas is supplied.
[0008]
Thus, until the raw material (2) and the seed crystal (5) reach a predetermined temperature and the pressure in the reaction vessel (1) reaches the predetermined pressure, the seed crystal (5) is covered with the shielding plate (6). If the seed crystal (5) is covered and the sublimation gas of the raw material (2) is shut off, the seed crystal (5) is covered during the period when the Si / C ratio is likely to fluctuate. No single crystal is formed on the crystal (5).
[0009]
Further, since the Si droplets are not generated in the seed crystal (5) due to the fluctuation of the Si / C ratio, and the graphite fine particles and metal impurities are not mixed, the seed crystal (5) is improved in quality. Can be maintained.
Therefore, when the raw material (2) and the seed crystal (5) reach a predetermined temperature and the pressure in the reaction vessel (1) reaches the predetermined pressure, a single crystal is formed on the high-quality seed crystal (5). Therefore, a high quality single crystal can be formed.
[0011]
In the invention according to claim 2 , the shielding plate (6) is arranged in a direction facing the surface of the single crystal in accordance with the growth rate of the single crystal so that the distance between the shielding plate (6) and the single crystal becomes a constant distance. ) Is moved. Thus, if the distance between the growth surface of the single crystal and the shielding plate (6) is always set to a predetermined distance, the temperature difference between the growth surface of the single crystal and the shielding plate (6) is kept constant. For this reason, the temperature of the growth surface of the silicon carbide single crystal is kept at a uniform and constant temperature, and a high-quality single crystal having the same polymorphism and few crystal defects can be formed.
[0012]
Preferably, the invention of claim 1 or 2 is applied to a method for producing a silicon carbide single crystal as shown in claim 3 . In the invention according to claim 4 , the raw material (2) disposed in the reaction vessel (1) is heated and sublimated to grow a single crystal on the seed crystal (5) fixed to the inner wall of the reaction vessel (1). In the single crystal production apparatus, an opening (1c) communicating with the inside and outside of the reaction vessel (1) is formed in the reaction vessel (1), and a support shaft (7) is disposed in the opening (1c), By moving the support shaft (7) from the outside of the reaction vessel (1), the shielding plate (6) is moved so that the seed crystal (5) and the raw material (2) can be blocked. It is characterized by that.
[0013]
In this way, by moving the support shaft (7) from the outside of the reaction vessel (1), the shielding plate (6) can be moved to block between the seed crystal (5) and the raw material (2). By doing so, Si droplets are generated in the seed crystal (5) due to fluctuations in the Si / C ratio during the period when the Si / C ratio is likely to fluctuate, and graphite fine particles and metal impurities are mixed. Since it is possible to shut off the seed crystal (5) and the raw material (2) while it is easily processed, a high-quality single crystal can be produced.
[0014]
In addition, as shown in claim 5 , when the seed crystal (5) is fixed to the upper surface of the reaction vessel (1), the opening (1c) is formed on the bottom surface of the reaction vessel (1). If the crystal (5) is formed at a position corresponding to the position where the crystal (5) is arranged, the shielding plate (6) can be moved in a direction facing the surface of the seed crystal (5) in accordance with the growth rate of the single crystal. An effect similar to that of the second aspect can be obtained.
[0015]
In addition, as shown in claim 6 , at least the surface facing the seed crystal (5) of the blocking plate (6) is made of a material lower than the saturated vapor pressure at a predetermined temperature of the inner wall material of the reaction vessel (1). For example, gas does not come out from the shielding plate (6) itself and reach the seed crystal (5).
Further, as shown in claim 7 , at least the surface of the blocking plate (6) facing the seed crystal (5) may be formed of silicon carbide. In this case, even if silicon carbide is sublimated, silicon is sublimated together with carbon, so that Si / C fluctuation does not occur and no influence due to Si / C fluctuation occurs.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
In FIG. 1, the schematic diagram of the single-crystal manufacturing apparatus used in this embodiment is shown. In FIG. 1, the vertical direction on the paper indicates the vertical direction.
[0017]
The single crystal manufacturing apparatus includes a graphite crucible 1, and carbonized on a silicon carbide single crystal substrate 5 as a seed crystal by sublimating a silicon carbide raw material 2 filled in the graphite crucible 1 by heat treatment. A silicon single crystal is grown.
The graphite crucible 1 is composed of a cup-shaped crucible main body 1a having an open upper surface and a lid 1b that closes the opening 1c of the crucible main body 1a. And the cover material 1b of this graphite crucible 1 becomes a base which supports the silicon carbide single crystal substrate 5 which is a seed crystal.
[0018]
Further, in the bottom surface of crucible body 1a, a position corresponding to the position where silicon carbide single crystal substrate 5 is arranged, that is, a position intersecting with the direction of the surface of silicon carbide single crystal substrate 5, penetrates this bottom surface. An opening 1c is formed. The opening 1c is formed in a hollow shape protruding from the bottom surface of the graphite crucible 1 in the direction of the lid 1b (direction perpendicular to the bottom surface), and the silicon carbide raw material 2 is disposed in the graphite crucible 1. The protruding part is higher than the silicon carbide raw material 2.
[0019]
A support shaft 7 for supporting the shielding plate 6 is disposed in the opening 1c of the graphite crucible 1. The support rod 7 is shielded by moving the support shaft 7 in the vertical direction (the arrow direction in the figure). The plate 6 is moved together so that the shielding plate 6 can cover or expose the silicon carbide single crystal substrate 5 serving as a seed crystal. At this time, the opening 1c of the graphite crucible 1 is closed by the support shaft 7 so that the graphite crucible 1 becomes a closed system.
[0020]
The shielding plate 6 is made of a material lower than the saturated vapor pressure at a predetermined temperature of the inner wall material of the graphite crucible 1. Here, the saturated vapor pressure refers to the maximum pressure at which the material can exist at a certain temperature. That is, the material is selected in order to prevent the shielding plate 6 from evaporating to generate gas and the gas from reaching the silicon carbide single crystal substrate 5. Specifically, refractory metals such as tantalum, tungsten, and molybdenum, or carbides (TaC, WC, MoC, etc.) of these refractory metals can be used as the material of the shielding plate 6.
[0021]
Further, the graphite crucible 1 can be heated by a heater 8 in a vacuum container into which an alkone gas can be introduced. By adjusting the power of the heater 8, the silicon carbide single crystal substrate 5 which is a seed crystal is heated. The temperature is kept about 100 ° C. lower than the temperature of the silicon carbide raw material 2.
A procedure for manufacturing a silicon carbide single crystal using the single crystal manufacturing apparatus configured as described above will be described.
[0022]
First, as shown in FIG. 1, a silicon carbide single crystal substrate 5 to be a seed crystal is bonded and fixed to a lid 1b with an adhesive or the like, and the lid 1b to which the silicon carbide single crystal substrate 5 is fixed is attached to the crucible body 1a. It arrange | positions in the opening part 1c. Then, shielding plate 6 is moved upward together with support shaft 7 so that silicon carbide single crystal substrate 5 is completely covered with shielding plate 6.
Thereafter, the pressure in the graphite crucible 1 and the temperatures of the silicon carbide raw material 2 and the silicon carbide single crystal substrate 5 are changed as shown in FIG.
[0023]
First, the inside of the graphite crucible 1 is set to an argon gas atmosphere, and the pressure is set to 500 Torr. Further, the heater 8 is heated so that the temperature of the silicon carbide raw material 2 is about 2400 ° C. and the temperature of the silicon carbide single crystal substrate 5 which is a seed crystal is about 2300 ° C. Thereafter, while maintaining the temperature of the silicon carbide raw material 2 at about 2400 ° C. and the temperature of the silicon carbide single crystal substrate 5 at about 2300 ° C., the pressure in the argon gas atmosphere in the graphite crucible 1 is reduced to about 1 Torr.
[0024]
The steps so far belong to a region (hereinafter referred to as region A) until the growth conditions shown in FIG. 2 become constant. In this region A, the silicon carbide single crystal substrate 5 which is a seed crystal is attached to the shielding plate 6. It is completely covered with. As described above, in this region A, the Si / C ratio is likely to fluctuate, and the formation of Si droplets and the incorporation of graphite fine particles and metal impurities into the single crystal are likely to occur. Since silicon carbide single crystal substrate 5 is covered with 6, silicon carbide single crystal substrate 5 is not affected by fluctuations in the Si / C ratio, and Si droplets are generated, or silicon carbide single crystal substrate 5 is formed in silicon carbide single crystal substrate 5. Unnecessary things such as graphite fine particles are not mixed. Thereby, also in region A, silicon carbide single crystal substrate 5 can be maintained as a high-quality seed crystal.
[0025]
Subsequently, when the pressure of the argon gas atmosphere in the graphite crucible 1 becomes 1 Torr, the shielding plate 6 is moved downward by the support shaft 7 so that the shielding plate 6 is separated from the silicon carbide single crystal substrate 5 for a predetermined time. Thus, silicon carbide single crystal substrate 5 is exposed. Then, the pressure of the argon gas atmosphere is adjusted to 1 Torr while feedback adjusting the power of the heater 8 so that the temperature of the silicon carbide raw material 2 is maintained at about 2400 ° C. and the temperature of the silicon carbide single crystal substrate 5 is maintained at about 2300 ° C. Keep it.
[0026]
This stage is a region in which the growth conditions shown in FIG. 2 are constant (hereinafter referred to as region B), and is a region that is in a stable state suitable for the temperature conditions and pressure conditions for crystal growth of the silicon carbide single crystal. In such a region B, since the fluctuation of the Si / C ratio is reduced, there is no such problem as described above, and the silicon carbide single crystal can be preferably grown. Therefore, since silicon carbide single crystal substrate 5 is exposed for the first time in such a region B, a silicon carbide single crystal can be suitably grown on a high-quality seed crystal.
[0027]
Thereafter, the shielding plate 6 is moved downward together with the support shaft 7 in accordance with the crystal growth rate of the silicon carbide single crystal so that the distance between the growth surface of the silicon carbide single crystal and the shielding plate 6 is always a predetermined interval. To do. As described above, when the distance between the growth surface of the silicon carbide single crystal and the shielding plate 6 is always set to a predetermined distance, the growth surface of the silicon carbide single crystal and the shielding plate 6 are opposed to each other. The temperature difference of the shielding plate 6 is kept constant. As a result, the temperature of the growth surface of the silicon carbide single crystal is kept at a uniform and constant temperature, and a high-quality bulk silicon carbide single crystal (silicon carbide single crystal ingot) having the same polymorphism and few crystal defects is obtained. It is formed.
[0028]
Furthermore, remove the silicon carbide Tan'yui crystallized from lid 1b of the graphite crucible, slicing the obtained crystal, semiconductor wafers made of silicon carbide single crystal by polishing is completed. Thus, until the temperature of the silicon carbide single crystal substrate 5 and the silicon carbide raw material 2 and the pressure in the graphite crucible 1 become stable (between the regions A), the silicon carbide single crystal is formed on the shielding plate 6. By covering the substrate 5, the silicon carbide single crystal substrate 5 is affected by the fluctuation of the Si / C ratio, or unnecessary particles such as graphite fine particles are mixed in the silicon carbide single crystal substrate 5. Thus, a silicon carbide single crystal having the same polymorph and having few defects can be formed on the silicon carbide single crystal substrate 5 which is a high-quality seed crystal.
[0029]
The crystal plane orientation of the wafer by X-ray diffraction and Raman spectroscopy, a result of determining the crystal structure (polymorphism), silicon carbide Tan'yui crystal is confirmed to have a 6H-type (0001) plane orientation It was. A semiconductor device such as a high-power vertical MOSFET, a pn diode, or a Schottky diode can be manufactured using the wafer thus completed.
[0030]
(Second Embodiment)
FIG. 3A shows a single crystal manufacturing apparatus according to this embodiment. FIG. 3B shows a cross-sectional view taken along the line AA in FIG. Since the single crystal manufacturing apparatus in the present embodiment has substantially the same configuration as the single crystal manufacturing apparatus in the first embodiment, only the parts different from the single crystal manufacturing apparatus in the first embodiment will be described.
[0031]
In the single crystal manufacturing apparatus in the first embodiment, a support shaft 7 that supports the shielding plate 6 is arranged in the opening 1c provided on the bottom surface of the crucible body 1a, and the shielding plate 6 is moved in the vertical direction together with the support shaft 7. The silicon carbide single crystal substrate 5 can be covered or exposed by the shielding plate 6 by being moved, but in this embodiment, a support shaft that supports the shielding plate 6 on the side wall surface of the crucible body 1a. 7 and the shielding plate 6 is moved in the horizontal direction together with the support shaft 7 so that the silicon carbide single crystal substrate 5 can be covered or exposed by the shielding plate 6. Therefore, the single crystal manufacturing apparatus in the present embodiment is different from the single crystal manufacturing apparatus in the first embodiment in the following points.
[0032]
In the present embodiment, the crucible main body 1a has an upper surface, and only a portion of the upper surface to which the lid member 1b is attached is open. The crucible body 1a is provided with a hollow housing portion 1d partially protruding outside the graphite crucible 1 on the side wall surface, and a support shaft 7 is disposed in the housing portion 1d and a shielding plate. 6 can be accommodated.
[0033]
Specifically, a communication port is formed in the accommodating portion 1d so as to communicate between the inside and the outside of the graphite crucible 1, and a support shaft 7 is arranged in the communication port, and the horizontal direction as indicated by an arrow in the figure. The direction can be moved. The shielding plate 6 is accommodated in the accommodating portion 1d when the support shaft 7 is moved to the right in the drawing.
On the other hand, lid 1b has a cup shape, and silicon carbide single crystal substrate 5 is accommodated in lid 1b. Then, when the support shaft 7 is moved to the left in the drawing, the shielding plate 6 covers the entire lid 1d. The upper surface of the crucible body 1a and the shielding plate 6 are in contact with each other, and the silicon carbide single crystal substrate 5 is shielded from the sublimation gas of the silicon carbide raw material powder by the shielding plate 6.
[0034]
As described above, the shielding plate 6 can be moved in the horizontal direction together with the support shaft 7 so that the temperature of the silicon carbide raw material 2 and the silicon carbide single crystal substrate 5 as a seed crystal and the pressure in the graphite crucible 1 are stable. By covering the silicon carbide single crystal substrate 5 built in the lid 1b with the shielding plate 6 until the state is reached, the silicon carbide single crystal substrate 5 is held as a high-quality seed crystal as in the first embodiment. be able to. Thereby, a silicon carbide single crystal having few defects and having the same polymorph can be formed on silicon carbide single crystal substrate 5 which is a high-quality seed crystal.
[0035]
(Third embodiment)
FIG. 4A shows a single crystal manufacturing apparatus according to this embodiment. FIG. 4B shows a cross-sectional view taken along the line BB in FIG. Since the single crystal manufacturing apparatus in the present embodiment has substantially the same configuration as the single crystal manufacturing apparatus in the first embodiment, only the parts different from the single crystal manufacturing apparatus in the first embodiment will be described.
[0036]
In the present embodiment, the support rod 7 is rotated without being moved in the vertical direction or the horizontal direction, so that the silicon carbide single crystal substrate 5 as the seed crystal can be covered or exposed by the shielding plate 6. Yes. Therefore, the single crystal manufacturing apparatus in the present embodiment is different from the single crystal manufacturing apparatus in the first embodiment in the following points.
Three holes communicating with the inside and outside of the graphite crucible 1 are formed at the same height on the side wall of the cup-shaped crucible body 1a. 7c is arranged. The three support shafts 7a to 7c are respectively provided with shielding plates 6a, 6b, and 6c. When the surfaces of the shielding plates 6a to 6c are in a horizontal state, the shielding plates 6a to 6c are made of graphite. The crucible 1 has a circular shape similar to the cross-sectional shape in the horizontal direction, and the space provided with the silicon carbide raw material 2 and the space provided with the silicon carbide single crystal substrate 5 are blocked.
[0037]
In this way, the shielding plates 6a to 6c can be rotated together with the support shafts 7a to 7c, and the temperature of the silicon carbide raw material 2 and the silicon carbide single crystal substrate 5 as the seed crystal, and the pressure in the graphite crucible 1 are adjusted. By covering the silicon carbide single crystal substrate 5 built in the recess of the lid 1b with the shielding plates 6a to 6c until the stable state is reached, the silicon carbide single crystal substrate 5 is made of a high quality seed as in the first embodiment. It can be maintained as crystals. Thereby, a silicon carbide single crystal having few defects and having the same polymorph can be formed on silicon carbide single crystal substrate 5 which is a high-quality seed crystal.
[0038]
In the present embodiment, the shielding plates 6a to 6c and the side wall surface of the crucible body 1a need to be spaced apart from each other so that the shielding plates 6a to 6c can rotate. If the space provided and the space provided with the silicon carbide single crystal substrate 5 can be cut off to some extent, the above effect can be obtained sufficiently.
(Other embodiments)
In the first to third embodiments, the temperature of the silicon carbide single crystal substrate 5 that is the silicon carbide raw material 2 and the seed crystal and the pressure in the graphite crucible 1 are in a stable state, that is, the temperature and pressure are detected. However, the stable state may be set when a crystal having the same composition as the composition of the silicon carbide single crystal substrate 5 adheres to the inner wall of the graphite crucible 1. That is, when a crystal having the same composition as the silicon carbide single crystal substrate 5 adheres to the inner wall of the graphite crucible 1, the condition for growing the silicon carbide single crystal has been reached. The composition of crystals adhering to the inner wall of the graphite crucible 1 can be detected using a mass spectrometer or the like.
[0039]
In the third embodiment, the three spindle rods 7a to 7c and the shielding plates 6a to 6c are provided and the silicon carbide single crystal substrate 5 is covered or exposed, but only by one spindle rod and the shielding plate. The silicon carbide single crystal substrate 5 may be covered or exposed. In this case, as shown in FIG. 5, the space other than the shielding plate 6 is made such that the crucible body 1 a protrudes into the interior of the graphite crucible 1 so that the space provided with the silicon carbide raw material 2 and the silicon carbide single crystal substrate. The space provided with 5 can be shut off.
[0040]
The shielding plate 6 is made of a material lower than the saturated vapor pressure of the inner wall material of the graphite crucible 1 at a predetermined temperature, but at least the surface of the shielding plate 6 facing the silicon carbide single crystal substrate 5 (seed crystal). If it is made of the above material, it is possible to prevent gas from being emitted from the shielding plate 6. Further, even if gas is emitted from the shielding plate 6, it is sufficient if it has the same Si / C ratio as the silicon carbide single crystal to be finally formed. The facing surface may be formed of SiC. Further, in the graphite crucible 1, the temperature of the shielding plate 6 is lower than that of the silicon carbide raw material 2, so that the sublimation amount from the shielding plate 6 is smaller than the sublimation amount from the silicon carbide raw material 2, and the shielding plate Even if silicon or carbon gas is generated from 6, it can be said that the silicon carbide single crystal 5 has little influence.
[Brief description of the drawings]
FIG. 1 is a schematic view of a single crystal manufacturing apparatus according to a first embodiment.
FIG. 2 is a time chart showing the temperature of seed crystals and silicon carbide raw material, and the pressure in the graphite crucible.
FIG. 3 is a schematic view of a single crystal manufacturing apparatus in a second embodiment.
FIG. 4 is a schematic view of a single crystal manufacturing apparatus in a third embodiment.
FIG. 5 is a schematic view of a single crystal manufacturing apparatus according to another embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Graphite crucible, 1a ... Crucible body, 1b ... Lid member, 1c ... Opening part,
2 ... silicon carbide raw material, 5 ... silicon carbide single crystal substrate (seed crystal), 6 ... shielding plate,
7 ... Spindle bar.

Claims (7)

  A method for producing a single crystal, in which a raw material (2) disposed in a reaction vessel (1) is heated and sublimated and a single crystal is grown on the seed crystal (5) while maintaining the inside of the reaction vessel (1) at a predetermined pressure. , Until the temperature of the raw material (2) and the seed crystal (5) reaches a predetermined temperature, and until the pressure in the reaction vessel (1) reaches the predetermined pressure. 5) is covered with a shielding plate (6) to block the sublimation gas of the raw material (2) from the seed crystal (5), and then the shielding plate (6) is moved to transfer the raw material to the seed crystal (5). (1) A method for producing a single crystal, comprising supplying a sublimation gas. The shielding plate (6) is moved in a direction facing the surface of the single crystal in accordance with the growth rate of the single crystal so that the distance between the shielding plate (6) and the single crystal is a constant distance. The method for producing a single crystal according to claim 1 . The method for producing a single crystal according to claim 1 or 2 , wherein the raw material (2) is a silicon carbide raw material, and the single crystal is a silicon carbide single crystal.   In the single crystal production apparatus, the raw material (2) disposed in the reaction vessel (1) is heated and sublimated to grow a single crystal on the seed crystal (5) fixed to the inner wall of the reaction vessel (1). An opening (1c) formed in the container (1) and communicating with the inside and outside of the reaction container (1) and the opening (1c), and the seed crystal (5) from the opening (1c) A support shaft (7) extending to the end of the support shaft (7), and a shielding plate (6) disposed at the end of the support shaft (7). By moving, the said shielding board (6) can be moved and the seed crystal (5) and the said raw material (2) can be interrupted | blocked, The single crystal manufacturing apparatus characterized by the above-mentioned. The reaction vessel (1) has a cylindrical shape, and the seed crystal (5) is fixed to the upper surface of the reaction vessel (1), and the opening (1c) It is formed in the position corresponding to the position where the said seed crystal (5) is distribute | arranged among the bottom surfaces of (1), The said shielding board (6) with the said support bar (7) is the said seed crystal (5). The single crystal manufacturing apparatus according to claim 4 , wherein the single crystal manufacturing apparatus is movable in a direction opposite to the surface. The surface facing at least the seed crystal (5) of the blocking plate (6) is made of a material lower than the saturated vapor pressure at the predetermined temperature of the inner wall material of the reaction vessel (1). The single crystal manufacturing apparatus according to claim 4 or 5 . The single crystal manufacturing apparatus according to claim 4 or 5 , wherein at least a surface of the shielding plate (6) facing the seed crystal (5) is made of silicon carbide.

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